1. Technical Field
The present disclosure relates to audio systems and input modalities therefor, and more particularly, to the input of time delay values to a signal processor.
2. Related Art
An audio system is comprised of several discrete but interconnected components that cooperate with each other to reproduce sound. As is well-understood in the art, waves of pressure changes in the air or other transmission medium is discerned as sound. This last segment of wave propagation is achieved with an acoustic transducer, also referred to as a loudspeaker, which converts electrical signals representative of the sound to corresponding physical movements of a diaphragm. The electrical signal of the sound may be stored as an analog waveform or a sequence of digital data representative thereof. In the case of digital audio, there may be a digital-to-analog converter (DAC) that processes the data, and generates analog voltage values corresponding to such data values for output to the loudspeaker. Digital audio may be stored in removable media such as compact discs (CDs), hard disk drives, and solid state memory devices, while analog audio may be stored on cassette tapes, vinyl records, and so forth.
Regardless of the source from which the electrical signals corresponding to the audio is generated, the component that generates such signals typically do not generate sufficient output power to drive the loudspeakers. To this end, most audio systems incorporate an audio power amplifier.
The audio signal may undergo additional processing prior to being output to the loudspeaker. One signal processing step is equalization, where the volume of discrete frequency ranges are increased or decreased so that the entire range of frequencies in the audio signal sounds balanced. In the most sophisticated audio systems, the equalizer may be used to fine-tune the volume of each instrument, which is understood to generate sound over specific frequency ranges. Other signal processors include limiters, compressors, noise gates, and expanders. Various effects may be applied to the audio signal as well, such as reverb, delay, pitch correction, distortion effects.
Because of binaural hearing, audio is recorded and reproduced in at least two channels—a left channel and a right channel. A loudspeaker positioned to the left side of the listener may receive the left channel audio, while another loudspeaker positioned to the right side of the listener may receive the right channel audio. In order to provide an even fuller listening experience, more channels that are connected to additional loudspeakers that are positioned in corresponding locations to the listener may be provided.
Almost all modern automobiles are equipped with audio systems, by which various entertainment and information content may be presented to the driver and the passengers. Such audio systems are pre-installed by the automobile manufacturer, and may be referred to as stock or OEM (original equipment manufacturer) components. In vehicle installations, loudspeakers are mounted in various locations throughout its interior, and like home installations, are connected to left channel audio outputs and right channel audio outputs, among other possible channels. Furthermore, a given speaker design may have a limited frequency response that does not span the entirety of the audible frequency range, so different types of loudspeakers, from tweeters, mid-range drivers, and subwoofers may be installed. With stock/OEM systems, the enclosures for the loudspeakers are built directly into the interior vehicle panels. The radiating element of the loudspeaker may be protected with a grille that is likewise integral with the vehicle interior, and may be surrounded by dampening material to minimize excess vibration.
In order to mitigate the effects of a poorly imaged soundstage, and/or to reduce phasing-based losses of bass frequency components in the audio, a delay audio processor may be utilized. Typically, such delay audio processors include one or more input modalities by which the delay factor applied to each channel can be adjusted. The specific delay value may be shown on a display screen for the installer or user to confirm that the desired value has been set. Alternatively, the delay may be programmed via a remote computer system that is connected to the delay audio processor. However, each of these solutions have proven to be expensive, and require a non-volatile memory device to retain the most recent delay values. Accordingly, there is a need in the art for an improved signal processor delay input device.